Device for building up fluid pressure pulses

ABSTRACT

A device for building up fluid pressure pulses comprises a cylinder and a piston which divides the cylinder cavity into two chambers. The first of these chambers communicates with a compressed gas vessel while the second one is filled with fluid and has a hole for the discharge of the fluid under pressure when the fluid is struck upon by the piston which is accelerated by the compressed gas in the first chamber, the second chamber being in constant communication with the fluid supply line through a number of channels in the sidewall of the cylinder, some of these channels being arranged tangentially to the chamber and inclined with respect to the axis of the discharge hole while the remainder of these channels are arranged radially and also inclined relative to the axis of the hole.

United States Patent 3,614,271

[72] inventors Vladimir Semenovich Muchnik [56] References Cited Kemerovskoi oblasti, ulitsa Michurina 5, UNITED STATES PATENTS 29; 2,688,514 9/1954 Oishei etal. 239/332 German Petrovich Chermensky,

Kemerovskoioblastiulim Nevskago 4,!- 3,234,737 2/1966 l-hiand 417/379 X 3; Mikhail Andreevi h Nikij v, Primary Examiner-Robert M. Walker Kememvskoi oblasfi, ulitsa Kirova, 33, kv, Attorney-Waters, ROditi, Schwartz & Nissen l9; Jury Vladimirovich Gaiduk,

ff:g'lr ftmgzfiffmfg fgggf" ABSTRACT: A device for building up fluid pressure pulses [2]] APPLNO. 872,534 comprises a cylinder and a piston which divides the cylinder [22] Filed Oct 30, 1969 cavity Into two chambers. The first of these chambers commu- [45] patented Oct 19, 1971 nicates with a compressed gas vessel while the second one is filled with fluid and has a hole for the discharge of the fluid under pressure when the fluid is struck upon by the piston which is accelerated by the compressed gas in the first [54] DEVICE FOR BUILDING UP FLUID PRESSURE chamber, the second chamber being in constant communica- PULSES tion with the fluid supply line through a. number of channels in 3 Claims 2 Drawing Figs the sidewall of the cylinder, some of these channels being ar- [52] U.S. Cl. 417/379 ranged tangentially to the chamber and inclined with respect [51] Int. Cl F04b 17/00 to the axis of the discharge hole while the remainder of these [50] Field of Search 417/379 channels are arranged radially and also inclined relative to the 375; 239/332 axis of the hole.

PATENTEnnm 19 I9?! 3, 6 1 4. 271

SHEET 1 OF 2 DEVICE FOR BUILDING UP FLUID PRESSURE PULSES The present invention relates to devices for building up ultrahigh fluid pressure pulses produced by the impact action of a piston on the fluid in a chamber having a hole for the discharge of fluid under pressure.

More specifically, the present invention relates to an improvement in the supply of fluid to the chamber of these devices.

The present invention can be used successfully for breaking up rocks with high-pressure fluid jets for hydraulic drop forging in which case the fluid discharged under pressure from the chamber by the impact of the piston is fed into a die with the blank, as well as for forging, pressing and cutting of metals in which case the fluid discharged from the chamber acts upon a movable piston carrying the working tool.

Known in the prior art are such devices, for example those described in the U.S. Pat. No. 3,412,554 granted to B. V. Voitzekhovsky et al. These devices have a cylinder with a piston reciprocating inside and dividing the cylinder into two chambers. The first chamber communicates with a compressed gas vessel while the second one is filled with fluid and has a hole through which the fluid is discharged under pressure as a result of the impact thereon by the piston which is moved by the compressed gas contained in the first chamber.

To return the piston to the initial position after the impact, the fluid in the known devices is fed under pressure into the cylinder at the side of the second-chamber, with simultaneous filling of said chamber. To prevent the fluid from escaping from the chamber before the impact, special automatic locking mechanisms have been provided which have closed the hole of the chamber and retained the fluid in the chamber before the impact.

The use of such locking mechanisms has complicated the design of the known devices and their industrial application since proper functioning of saidmechanisms requires the use of clean fluid, free of any mechanical impurities, and such a fluid is not always readily available.

Therefore, attempts have been made to dispense with the locking mechanisms. It has been suggested to pass the fluid in a continuous stream through the second chamber in a direction perpendicular to the movement of the piston and to make the piston impart periodic blows to this stream of fluid.

However, in this case the jet of fluid produced by a free acceleration of a certain quantity of fluid in the chamber has been abundantly saturated with air and intensively sprayed im mediately after leaving the chamber. The work done by such a jet has proved to be inefficient.

An object of the invention is to provide a device for building up fluid pressure pulses with an improved supply of fluid into its chamber. The device according to the invention comprises a cylinder with a piston which divides said cylinder cavity into two chambers, one of which is in communication with a compressed gas vessel while the second one is filled with fluid and has a hole for the discharge of the fluid under pressure when said fluid is struck by the piston which is accelerated by the compressed gas contained in the first chamber. The improve ment consists in that the sidewall of the cylinder around the second chamber has several channels connected with the fluid supply line; some of the channels extend tangentially to the space of this chamber while being inclined to the axis of the hole while the other channels are directed radially while also being also inclined to the axis of the hole.

It is desirable that the tangential channels alternate with the radial ones so that the tangential channels can be inclined with respect to the hole axis at a smaller angle than the radial channels and be located somewhat ahead of them.

In one of the preferable embodiments of the invention all the channels can be interconnected by an internal circular recess communicating with a circular vessel located outside the cylinder and connected with the fluid supply line.

One advantage of the device is that the chamber is completely filled with fluid without the use of any locking mechanisms.

Another advantage of the invention is that the fluid contained in the chamber is not saturated with air because the rotary movement of the fluid created by its tangential supply prevents such a saturation and the hollow vortex produced during the rotation of the fluid is simultaneously filled with additional fluid supplied through the radial channels.

Still another advantage of the invention is that the produced vortices atomize the fluid leaking out of the chamber before the impact, thus freeing the path for the high-pressure jet; as a result, this jet becomes more compact at a considerable distance from the hole after the discharge from the chamber.

Other features and advantages of the invention will become apparent from the description which follows with reference to the accompanying drawings, in which:

FIG. 1 is a schematic diagram of the device according to the invention at the moment when the piston after the impact is located in the second chamber and is not connected with the cocking mechanism; and

FIG. 2 is an enlarged sectional view taken along line II-lI of FIG. 1.

The device comprises a cylinder 1 (FIG. I) with a piston 2 which divides the cavity of the cylinder ll into two chambers 3 and 4. The first chamber 3 is in constant communication with a compressed gas vessel 5 while the second chamber 4 is constantly connected to the fluid supply line 6 via a throttle 7 and has a hole 9 in the end wall 8 of the cylinder 1 for the discharge of fluid under pressure, this discharge being caused by the impact of the piston 2 accelerated by compressed gas in the chamber 3.

The pressure of fluid in the chamber 4 when said fluid is struck by the piston 2 rises high above the pressure of gas in the chamber 3 so that the chamber 4 is a high-pressure chamber while the chamber 3 is a low-pressure one. In view of this fact the walls of the cylinder l in the region of the chamber 4 are considerably thickened and are made in several layers.

The fluid flows from the supply line 6 into the chamber 4 through a circular vessel 10 located outside the cylinder I and adjoining the vertical channels 11 in its sidewall, said vertical channels opening into an internal recess 12 which communicates with the chamber 4 through channels 13 and I4.

The channels 13 are. arranged tangentially to the space of the chamber 4 as illustrated in FIG. 2 and inclined towards the axis of hole 9 whereas the channels 1.4 are arranged radially and are likewise inclined towards the axis of hole 9. The channels I3 and 14 are arranged in an alternating order and the channels 13 are inclined at a smaller angle to the axis of the hole 9 than the channels 14 and are located somewhat ahead of them ie closer to the hole 9. These angles are 30 and 45", respectively.

The fluid supplied into the chamber 4 through the channels 13 is swirled and forces out the air which has entered the chamber 4 while the piston 2 has been cocked. The fluid is pressed by the centrifugal forces against the walls of the chamber 4 and a vortex is formed in the center. The channels 114 feed fluid directly into this vortex, filling it and forcing the air out of it and out of the chamber 4. Simultaneously, the fluid is fed through the channels 15 (FIG. 11) into the gap between the piston 2 and the wall of tlhe cylinder 1 at the side of the chamber 4 thus creating a hydraulic brake to prevent the piston 2 from striking the cylinder I.

Since the fluid is continuously supplied into the chamber 4, its surplus quantity is drained through the hole 9 and, being rotated, it is pressed against the walls of the hole 9 and is atomized at the exit, thus freeing the path for the discharge of the high-pressure jet after the impact. Part of the fluid contained in the chamber 4 together with the fluid supplied into the above-mentioned gap is drained through the drain holes I6 in the sidewall of the cylinder 1 while the piston 2 is moving towards the chamber 3.

The provision of the vertical channels 11 and internal recess 12 is desirable from the technological point of view. In some cases, however the channels 113 and I4 may run throughout the entire thickness of the wall of the cylinder 1 in the chamber 4.

The piston 2 is returned to the initial position after the impact by a cocking mechanism 17 comprising a pair of power cylinders 18 one chamber 19 of which communicates with the fluid supply line 6 while the other chamber 20 communicates with the compressed gas vessel 5. The rods 21 of the pistons 22 of said cylinders are fastened to the crossarm 23 carrying a link 24 which passes into the chamber 3 through the end wall 25 of the cylinder 1. The end of the link 24 at the side of the chamber 3 has a space 26 accommodating a slide 27 which has a circular recess 28 and is connected with a crossbar 29 installed with a certain clearance in the ports 30 of the link 24. The wall of the link limiting the space 26 has ports 31 into which enter the cams 32 held in place by the slide 27. The earns 32 of the link 24 interact with the internal recess 33 in the end surface of the piston 2 directed towards the chamber 3.

This certainly is but one of the possible means for returning the piston 2 to the initial position. This can also be done by delivering the fluid under pressure into the chamber of the cylinder 1 at the side of the chamber 4 or by providing one cocking cylinder whose piston is moved in either direction by the fluid fed from the fluid supply line 6.

The device operates as follows.

When the piston 2 is in the chamber 4, the pistons 22 of the cylinders 18 are moved towards the chamber 19 by the pressure of gas in the vessel and the link 24 enters the recess 33 of the piston 2. The cams 32 are retracted in the ports 31, bearing against the recess 28 of the slide 27. When the slide 27 bears against the piston 2, the slide is moved through a distance equal to the clearance between the crossbar 29 and the ports 30 of the link 24, shifting the cams 32 from the ports 31 and engaging them with the piston 2. Then the pistons 22 of the cylinder 18 are moved by the fluid pressure towards the space 20, cocking the piston 2 which, in its turn, compresses gas in the chamber 3. As soon as the crossbar 29 bears against the wall 25 of the cylinder 1, the slide 27 moves towards the piston 2 so that its recess 28 becomes opposite the ports 31 and the cams 32 come out of the recess into the ports 31, having disengaged the piston 2. The latter, actuated by the compressed gas in the chamber 3 is accelerated in the cylinder 1 and strikes the fluid in the chamber 4. Then the process is repeated over again.

The device has been industrially tested and has provided stable service. The chamber 4 has been reliably filled with fluid regardless of the angle to the horizontal at which the device has been installed.

What we claim is:

l. A device for building up fluid pressure pluses comprising: a compressed gas vessel; a cylinder; a piston located inside said cylinder and dividing its cavity into two chambers, the first of which communicates with said compressed gas vessel and the second of which is filled with fluid and has a hole for the discharge of the fluid after it has been struck by the piston accelerated by the compressed gas in the first chamber of said cylinder; means for returning the piston to the initial position after the impact; a fluid supply line; said cylinder having a sidewall provided with several channels arranged around the second chamber and connected to said fluid supply line to supply fluid into said second chamber, some of said channels being arranged tangentially to the second chamber and inclined with respect to the axis of said hole while the remainder are arranged radially and are also inclined with respect to the axis of said hole.

2. A device as claimed in claim I wherein said tangential channels alternate with the radial ones and are inclined with respect to the axis of said hole at a smaller angle than the radial channels, and are closer to said hole.

3. A device as claimed in claim 1 wherein all of said channels are interconnected by an internal circular recess provided in said sidewall and communicating with a circular vessel located outside the cylinder and connected to the fluid supply line. 

1. A device for building up fluid pressure pluses comprising: a compressed gas vessel; a cylinder; a piston located inside said cylinder and dividing its cavity into two chambers, the first of which communicates with said compressed gas vessel and the second of which is filled with fluid and has a hole for the discharge of the fluid after it has been struck by the piston accelerated by the compressed gas in the first chamber of said cylinder; means for returning the piston to the initial position after the impact; a fluid supply line; said cylinder having a sidewall provided with several channels arranged around the second chamber and connected to said fluid supply line to supply fluid into said second chamber, some of said channels being arranged tangentially to the second chamber and inclined with respect to the axis of said hole while the remainder are arranged radially and are also inclined with respect to the axis of said hole.
 2. A device as claimed in claim 1 wherein said tangential channels alternate with the radial ones and are inclined with respect to the axis of said hole at a smaller angle than the radial channels, and are closer to said hole.
 3. A device as claimed in claim 1 wherein all of said channels are interconnected by an internal circular recess provided in said sidewall and communicating with a circular vessel located outside the cylinder and connected to the fluid supply line. 